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Sporthd6899
New member
Username: Sporthd6899
Post Number: 3
Registered: 2-2004
| | Posted on Sunday, May 14, 2006 - 1:57 am: | 
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OK. I'M STUPID!! I'VE BEEN CHECKING OUT THESE THEADS AND BEEN SEEING ALOT OF THE NPC-RC MODS, IF I'M CORRECT!! NOW CAN YOU PLEASE TELL ME WHAT EXACTLLY YOUR TALKING ABOUT, OR MEANS?? THANKS, ALOT!! |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1579
Registered: 9-2004
| | Posted on Sunday, May 14, 2006 - 6:56 pm: |
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NPC= Negative Peak Compression
RC= Reduced Carrier
the npc portion of the mod squeezes the negative peaks of your modulation to give a boost in modulation.
the RC part is to lower the dead key of the radio so you can run a linear while still having a high PEP wattage on modulation.
low deadkey, high swing.
thats what this mod is all about.
matt |
Sporthd6899
New member
Username: Sporthd6899
Post Number: 7
Registered: 2-2004
| | Posted on Wednesday, May 17, 2006 - 6:12 pm: |
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OK,THANKS FOR THE RESPONSE! I'VE JUST BEEN SEEING ALOT OF THIS TYPE OF MOD AND WASN'T TOO SURE WHAT IT WAS ALL ABOUT. CAN THIS BE DONE ON MY RANGER TR-969F MOBILE? AND IF SO WHATS THE PROCEGURE? AND CAN THIS MOD BE "VARABLE", OR NOT??
THANKS,
ROD |
Inspector
Intermediate Member
Username: Inspector
Post Number: 161
Registered: 12-2001
| | Posted on Thursday, June 01, 2006 - 4:15 am: |
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I have been discussing the subject on another site lately, with those that think the NPC-RC mods are BAD for your radios. When done correctly, the results are awsome and the radio will actually last longer than if you just "cranked it up". The problem is in that some of these mods use wrong parts or they are installed incorectly or the limmiters are removed of the instructions have bad info in them. Volting, I have seen, can be a waste of time in some radios and some radios it works fine...usually you only get an extra watt or so by volting, sometimes not worth the effort. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1746
Registered: 9-2004
| | Posted on Thursday, June 01, 2006 - 7:31 pm: |
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here is a link to the NPC mod for the VR9000.
should be VERY similar to many galaxy chssis.
http://www.copperelectronics.com/cgi-bin/discus4/board-auth.cgi?lm=1005637154&file=/7750/7758.html |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2923
Registered: 7-2004
| | Posted on Friday, June 02, 2006 - 6:29 pm: |
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you are 'volting' the final to get max watts out of it. you are at the same time, yup, supermodding it, to reduce the carrier & keep the swing high, & finally, semi-compressing the signal for more punch. done right....it works. RMS swing from the amp skyrockets as well.
anybody ever hear my grant XL |
Dale
Intermediate Member
Username: Dale
Post Number: 441
Registered: 12-2002
| | Posted on Monday, June 05, 2006 - 11:28 am: |
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its always nice 2 find a way 2 peak and tune your radio without having 2 clip your limiter or modify your amc circuits,or putting more volts into it.good job very well done.my only question is what kinda meter ya use 2 measure out 1.25 watts ...lol |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2936
Registered: 7-2004
| | Posted on Wednesday, June 07, 2006 - 5:05 pm: |
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it kinda sounds like the audio dies off just a bit on the top end-because you didn't volt the final. better voltage regulation may help, but just give the final some more volts to begin with & audio won't drop off . 'loudness' will be there & clarity will be unaffected when done right & the realization that 'crankin' it all the way up' is NOT doing ANYTHING good.
read hotwire's comments under 'CEF contacts' this week. my ar3500 at the base has a stock mic, & NO OTHER modifications or tweaks other then 'expanded xmit freqs', factory realignment & what came from the factory internally. my XL mobile's quality is nearly the same. an astatic road devil eliminates more background noise then the stock mic, & with the radio mic gain at 80% & mic's gain adjust up 1/8", it gets 'broadcast quality audio' signal reports on SSB & 'LOUD & crystal clear' on AM. that is the 'quality' of the uniden chassis itself, as well as 'restraint'. fine tune the voltage going to the final when 'volting', & when changing or removing resistors, ØW isn't always best for audio quality. you know you don't need WAHWAHWAHWAH-loud, muffled charlie brown sounding audio & 50 watts swing from the radio to make everything else work as planned. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2947
Registered: 7-2004
| | Posted on Friday, June 09, 2006 - 3:46 pm: |
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due to impending construction, my shack is in a shambles, & locating much more then the mic & radio that is attatched to the antenna is a bit rough. i can't give specific #'s.
1st, the audio dying off shows most likely a voltage problem, or lack thereof. if you haven't upgraded the voltage regulator, now would be the time to do it. should that not resolve the problem, you need some MORE voltage. 'volt' the final. i'm not sure why "'volting' will defeat the purpose". should longevity or performance be a concern, don't use the voltage that comes from the standard tapping point. if it's 8 or 12, find another source with less, but more then normal, or just add a resistor. that can tailor your PEP, carrier, audio quality-even tone. all trial & error. instead of 'clipping' the limiter, try changing its value, then put it on a switch. if checking results on a 'scope isn't possible, you can always 'check' using the bleedover method-have somebody listen at a certain distance where the cranked-but stock-radio doesn't bleed, & experiment with adjustments & tweaks for the least amount of bleedover, but loudest & clearest audio. the npc portion of the mod gives some light compression, pretty much the most you can get the radio to do without redesigning the circuitry. this adds punch as well as clarity. a full blown compressor would be overused by the average CBer & make audio unintelligible & just plain crummy.
i'm not sure why the discrepancies in coppers compression desk mic. i have yet to see one, & am going to wait til i see/hear some more of 'em. i think the mic may very well be working as intended-audio quality wise, not 'problems'. some may just be expecting to hear (locally) everybody say 'that is the loudest, most extreme audio i've ever heard'. but that is not the purpose of compression. 'punch' obtained through compression is more easily 'measured' in high noise conditions-where the 'compressed' signal shows more ability to cut through the noise.
another option, is to grab a couple of lou franklins 'dynamic speech processors'. forget what the intention of the name is. build 1 & experiment. i have just acquired 3 of them, after having not used them in nearly 20 years. they were tricky to make work back then. but again, back then, i too came from the school of 'crank it all the way'. i did get 'em to work, & well, too, when using restraint-reduced W's to the limiter-not outright removal, no power mic, cautious tweak & severe trial & error. once everything was adjusted right, wax over the pots so they wouldn't turn on their own. then leave 'em be. they increased talk-power on more then one stock radio i tried back then. time to start messing with 'em again.
the design of some radios causes them to respond differently to a particular mod. even 2 different of the same radio can cause that. experiment til you find what you like best & stick with it. i've said before i did every mod & trick to get every last watt & bit of audio out of a radio, then added a big amp. for my purposes, rebuilding a radio no longer serves any purpose. audio quality is obtained through reasonable mods. if you wanna stay legal, that's the best you can do, then add a directioanl antenna. if legality is of no concern, why bother tweaking for 50 loud, muffled & overmodulated watts, when 10 quality watts & a big amp works a hundred times better. |
Cdn_superpower
Member
Username: Cdn_superpower
Post Number: 50
Registered: 6-2005
| | Posted on Sunday, June 11, 2006 - 7:37 am: |
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I did the "swing" mod on my 2000, just how Kid explained it and it works great, the swing is insane
Anyway, I think the "volting"
is giving the final 13.8v instead of 8v, which on the 29ltd, the final gets a full 13.8v.
I seen this mod years ago on the net, there was reference to the long trace on VR10 and you cut it and put a 1/2 w resistor across it, but I can't find it anywhere and I forgot exactly how many ohm's the resistor was.
Regardless, if you have the 8719 dual conversion board your in !!!
Anything else is a gamble unless the powers that be have carefully designed one.
By the way been getting some Russian skip or something lately.....73's |
Bronzepony
Member
Username: Bronzepony
Post Number: 81
Registered: 12-2005
| | Posted on Saturday, November 25, 2006 - 9:22 am: |
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Can anyone post this for the 2000. |
Tech291
Moderator
Username: Tech291
Post Number: 458
Registered: 11-2004
| | Posted on Sunday, November 26, 2006 - 8:54 am: |
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Bronzepony,
in the left margin,use the search feature and type in cobra 2000 npc.youl find the info you want.
Tech291
CEF#291/CVC#6
kc8zpj |
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